Finally, we are going to get to the bottom of what happened during the deadly attack at the U.S. mission in Benghazi, Libya.

Or at least that is what Republicans in the U.S. House of Representatives are claiming. Earlier this week, House Speaker John Boehner appointed Rep. Trey Gowdy, R-S.C. and a former federal prosecutor, to lead a special committee not only to investigate how the September 2012 attack happened but also the White House's response. Four Americans, including Ambassador Christopher Stevens, were killed in the attack.

"Twenty months after the Benghazi attacks, there remain unresolved questions about why the security was inadequate, our response during the siege itself and our government's interaction with the public after the attack," Gowdy said in a statement.

If there are questions that remain unresolved, then lawmakers either are asking the wrong questions or simply don't like the answers. Thus far, Congress has conducted seven different Benghazi investigations, held 13 public hearings, 50 separate briefings and produced 25,000 pages of documents.

This eighth inquiry won't even halt four other congressional probes that remain ongoing.

What do we know thus far? Probably as much as we're going to know.

We know security at embassies and missions in Libya was inadequate, given the threat from Islamist militias that overthrew the late dictator Moammar Gadhafi. We know repeated requests for stronger security by Stevens and other officials were denied. We know Congress, particularly the Republican-led House, repeatedly slashed security funding for embassies and missions throughout the world.

We know there were no U.S. military units that could have reached Benghazi in time to change the outcome. We know the State Department did not delay deployment of the limited resources it had on hand.

We know it was the CIA's Office of Terrorism Assessment and not the White House that authored the quickly dispelled talking points then-U.N. Ambassador Susan Rice explained on the Sunday morning talk shows about how the attack was related to protests of the anti-Islam video "Innocence of Muslims."

And we know the loss of four Americans while in service of country is regrettable, lamentable and unacceptable.

But what will an eighth congressional inquiry determine that previous ones did not?

Nothing. But it will allow panel members to ask about an email sent from Deputy National Security Adviser Ben Rhodes to Rice that Boehner said was withheld from a congressional subpoena. The email said that Rice should "underscore that these protests are rooted in an Internet video, and not a broader failure of policy."

There have been multiple references to this email as the "smoking gun" the investigation has needed. We would disagree. This eighth, and probably not the last, congressional investigation is simply more of the same. No matter how the questions are asked, there will be no answer that is worded "The president lied" or "Obama caused these four to die." As those are the only answers that apparently would be acceptable, the latest probe is a waste of time and money.